Hydroxyapatite-supporting porous silica particles, method for producing hydroxyapatite-supporting porous silica particles, and composition comprising hydroxyapatite-supporting porous silica particles

Abstract

The present invention relates to a hydroxyapatite-supporting porous silica particle, in which hydroxyapatite is supported on a surface a spherical porous silica particle and inner surfaces of pores of the spherical porous silica particle, and in which the hydroxyapatite-supporting porous silica particle has a circularity of 0.760 or larger, a method for producing the hydroxyapatite-supporting porous silica particles, and a composition containing the hydroxyapatite-supporting porous silica particle.

The invention claimed is: 
     
         1 . Hydroxyapatite-supporting porous silica particles,
 wherein hydroxyapatite is supported on a surface of a spherical porous silica particle and inner surfaces of pores of the spherical porous silica particle,   wherein the hydroxyapatite-supporting porous silica particle has a circularity of 0.760 or larger, and   wherein the hydroxyapatite-supporting porous silica particles have an average particle diameter D 50  in a volume basis cumulative particle size distribution of from 2 μm to 500 μm.   
     
     
         2 . The hydroxyapatite-supporting porous silica particles according to  claim 1 ,
 wherein an amount of the supported hydroxyapatite is from 0.1 mass % to 80 mass % in the hydroxyapatite-supporting porous silica particles.   
     
     
         3 . The hydroxyapatite-supporting porous silica particles according to  claim 1 , having a ratio (C HAp /C CeO2 ) of C HAp  to C CeO2  of 1.0 or smaller,
 wherein the C HAp  is a maximum count number in a range of 2θ=31.5° to 32.5° corresponding to a (211) plane of the hydroxyapatite in an XRD pattern of the hydroxyapatite-supporting porous silica particles and the C CeO2  is a maximum count number in a range of 2θ=28.0° to 29.0° corresponding to a (111) plane of a cerium oxide in a separately measured XRD pattern of cerium oxide as an external standard.   
     
     
         4 . The hydroxyapatite-supporting porous silica particles according to  claim 1 , satisfying the following conditions (1)-(3),
 wherein when a unidirectional maximum particle diameter in a cross section of a hydroxyapatite-supporting porous silica particle is radially divided into a first portion, a second portion, and a third portion of three equal parts in a cross sectional image of the hydroxyapatite-supporting porous silica particle observed by SEM-EDX, a point analysis is performed at three points that are selected arbitrarily from a range of a circle having, as a diameter, a diameter length of the second portion located at the center and at three points that are selected arbitrarily from a range of a circle having, as a diameter, a diameter length of the first or third portion:   (1) an average value of an intraparticle variation coefficient of a peak signal intensity of calcium to a peak signal intensity of silicon is from 0% to 50%;   (2) an average value of an intraparticle variation coefficient of a peak signal intensity of phosphorus to a peak signal intensity of silicon is from 0% to 50%; and   (3) an average value of an intraparticle variation coefficient of a peak signal intensity of calcium to a peak signal intensity of phosphorus is from 0% to 50%.   
     
     
         5 . The hydroxyapatite-supporting porous silica particles according to  claim 1 , having a pore volume of from 0.05 mL/g to 2.50 mL/g. 
     
     
         6 . The hydroxyapatite-supporting porous silica particles according to  claim 1 ,
 wherein the hydroxyapatite-supporting porous silica particles have an oleic acid adsorption amount of 60 mg/g or higher when 0.5 g of the hydroxyapatite-supporting porous silica particles are mixed with 5 g of an imitation sebum solution containing oleic acid at a concentration of 16 mass %.   
     
     
         7 . A method for producing the hydroxyapatite-supporting porous silica particles according to  claim 1 ,
 wherein hydroxyapatite is produced by bringing a calcium source and a phosphorus source into contact with spherical porous silica particles each having a circularity of 0.560 or higher.   
     
     
         8 . The method for producing the hydroxyapatite-supporting porous silica particles according to  claim 7 , the method comprising:
 fixing calcium on the surfaces of the spherical porous silica particles and the inner surfaces of pores of the spherical porous silica particles by bringing a first solution containing the calcium source into contact with the spherical porous silica particles; and   producing hydroxyapatite by reacting the calcium with phosphorus by bringing a second solution containing the phosphorus source into contact with the calcium-fixed spherical porous silica particles.   
     
     
         9 . A composition for a skin, a composition for an oral cavity, a composition for an adsorbent, or a medicine composition containing the hydroxyapatite-supporting porous silica particles according to  claim 1 .